A reservoir may be a subsurface body of rock that includes sufficient porosity and permeability to store and transmit fluids. As an example, sedimentary rock may possess more porosity than various types of igneous and metamorphic rocks. Sedimentary rock may form under temperature conditions at which hydrocarbons may be preserved. A reservoir may be a component of a so-called petroleum system. A geologic environment may be a sedimentary basin that may include one or more fluid reservoirs.